With bunker fuel prices rising and increased interest in regulatory activities associated with reduced environmental impact, the improved hull efficiency[ds_preview] associated with clean hull operations is essential. Reported improvement in hull efficiency and the resulting decrease in fuel used range from 5–20%. That depends on numerous factors such as transit speed, coating condition, geographic area of operation, and current corporate hull cleaning practices. Progressive shipping companies with instrumented ships and other companies utilizing operational data are studying fuel efficiencies vs. cleaning protocols to refine their process. These efforts will result in newly defined best practices for ship operation. The Hull Bio-inspired Underwater Grooming (HullBUG) System developed by SeaRobotics with support from the US Navy and extensive testing performed by Florida Tech of Melbourne, Florida/USA. The HullBUG is a crawler robot that supports largely automated underwater ship hull cleaning. Hull grooming (i.e. light cleaning with focus on bio-film removal) can now be accomplished without divers, frequently and relatively cheaply. The robot uses various attraction mechanisms, including hydrodynamically generated negative pressure, and magnetic attraction for attachment to the hull surface. A multichannel fluorometer which automatically detects chlorophyll in the bio-film is utilized in the guidance system. Efficacy studies on numerous grooming methods on different coating types with variable periodicities have been studied. Utilizing advanced control algorithms and sensing systems, a highly automated hull grooming system is now a reality.
Don Darling
